using System;
using System.Runtime.InteropServices;
using nsISupports = System.Object;
using nsQIResult = System.Object;

namespace DotGecko.Gecko.Interop
{
	/**
	 * nsIArray
	 *
	 * An indexed collection of elements. Provides basic functionality for
	 * retrieving elements at a specific position, searching for
	 * elements. Indexes are zero-based, such that the last element in the
	 * array is stored at the index length-1.
	 *
	 * For an array which can be modified, see nsIMutableArray below.
	 *
	 * Neither interface makes any attempt to protect the individual
	 * elements from modification. The convention is that the elements of
	 * the array should not be modified. Documentation within a specific
	 * interface should describe variations from this convention.
	 *
	 * It is also convention that if an interface provides access to an
	 * nsIArray, that the array should not be QueryInterfaced to an
	 * nsIMutableArray for modification. If the interface in question had
	 * intended the array to be modified, it would have returned an
	 * nsIMutableArray!
	 *
	 * null is a valid entry in the array, and as such any nsISupports
	 * parameters may be null, except where noted.
	 */
	[ComImport, Guid("114744d9-c369-456e-b55a-52fe52880d2d"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
	public interface nsIArray //: nsISupports
	{
		/**
		 * length
		 *
		 * number of elements in the array.
		 */
		UInt32 Length { get; }

		/**
		 * queryElementAt()
		 *
		 * Retrieve a specific element of the array, and QueryInterface it
		 * to the specified interface. null is a valid result for
		 * this method, but exceptions are thrown in other circumstances
		 * 
		 * @param index position of element
		 * @param uuid the IID of the requested interface
		 * @param result the object, QI'd to the requested interface
		 *
		 * @throws NS_ERROR_NO_INTERFACE when an entry exists at the
		 *         specified index, but the requested interface is not
		 *         available.
		 * @throws NS_ERROR_ILLEGAL_VALUE when index > length-1
		 *
		 */
		[return: MarshalAs(UnmanagedType.Interface, IidParameterIndex = 1)]
		nsQIResult QueryElementAt(UInt32 index, [In] ref Guid uuid);

		/**
		 * indexOf()
		 * 
		 * Get the position of a specific element. Note that since null is
		 * a valid input, exceptions are used to indicate that an element
		 * is not found.
		 * 
		 * @param startIndex The initial element to search in the array
		 *                   To start at the beginning, use 0 as the
		 *                   startIndex
		 * @param element    The element you are looking for
		 * @returns a number >= startIndex which is the position of the
		 *          element in the array.
		 * @throws NS_ERROR_NOT_FOUND if the element was not in the array.
		 */
		UInt32 IndexOf(UInt32 startIndex, [MarshalAs(UnmanagedType.IUnknown)] nsISupports element);

		/**
		 * enumerate the array
		 *
		 * @returns a new enumerator positioned at the start of the array
		 * @throws NS_ERROR_FAILURE if the array is empty (to make it easy
		 *         to detect errors)
		 */
		nsISimpleEnumerator Enumerate();
	}
}
